M1 MacBook Teardowns: Something Old, Something New

Like Craig Federighi before us, today we’re opening up the new M1 MacBooks and seeing the light. Except… we opened them from the other side. Oops.

We’ll spill all the details below, but suffice to say, our curiosity has been rewarded in the most unintuitive way possible. While Apple touts its M1-powered Macs as nothing short of a revolution, internally, they could hardly be any more similar to their predecessors. The new 13” MacBook Pro looks so familiar inside, we had to double-check that we didn’t accidentally purchase the old model. Meanwhile, the new MacBook Air’s biggest move was to … eliminate the fan. Amazing, right? Well, in many ways, yes. Let’s dig into it.

MacBook Air—Now With Less Air(flow)

The biggest physical change to either of these machines is also the punniest: The Air no longer actively moves air. In what a pessimist might describe as pulling a Microsoft, Apple nixed the fan in favor of a simple aluminum heat spreader hanging off the left edge of the logic board. 

If that move has you groaning slightly, we understand. Recent history arguably warrants a little pessimism here. The Air hasn’t had the best track record with thermals—it was starting to gain a reputation—and the cooling solutions in some other Apple notebooks are famously anemic. So you might worry that the fan is the new headphone jack, an inevitable victim of designers obsessed with slim, light slabs and minimaluminiumalism. 

But there’s something to be said for the fanless simplicity of the iPad (Apple’s other computer). If this new thermal arrangement is truly enough to meet the M1’s needs—and early reviews indicate that for most workloads, it is—it means less maintenance and one less point of mechanical failure. Will anyone actually miss having to open their laptop to de-gunk or replace a dusty old fan? Maybe somebody will. Maybe even us. But let’s be real: the best repair is the one you never have to make in the first place. 

There’s just not much to go wrong here. A thick cold plate over the M1 processor draws heat via conduction to its flatter, cooler end, where it can safely radiate away. Without a fan, this solution may take longer to cool off, and may cap out sooner, but by foregoing heatpipes or a vapor chamber, the sink also has more mass to saturate with thermal energy. There are no moving parts, and nothing to break. You’ll want new thermal paste occasionally, and that’s about it.

Apart from the new board and cooler, the rest of the Air remains all but identical to its predecessor. There’s a new battery model, with minimally different specs. The repair procedures will likely remain almost totally unchanged. As for the board and the M1 itself, more on that below.

MacBook Pro—Mostly the Same, Which Is Different

The MacBook Pro sees even fewer internal changes than the Air, and in a way, that is a surprise in itself. We’d expected—nay, hoped—to see some consolidation of MacBook parts and design. These machines are, after all, running the same chip, and the same OS, on nearly identical screens. Interchangeable parts (such as we found in some of this year’s iPhones) would significantly increase your odds of finding replacements down the line, since more of them get produced. In a pinch, you can even pilfer parts from devices that aren’t exactly the same as yours. And the repair procedures tend to be similar if not identical.

But the two-port MacBook Pro and the new MacBook Air still hail from completely different evolutionary lines. Nowhere is that more apparent than in the Pro’s familiar thermal design. The M1 MacBook Pro’s cooling setup is very similar to that of its Intel-based ancestors: nothing fancy, just a copper heat pipe carrying heat away from the processor toward a small heatsink, where the hot air is promptly shown the door grille by the fan.

Speaking of the fan, there has been some light speculation that these new machines run so impossibly quiet even under heavy load, they might be concealing some nigh-magical new cooling tech. It turns out, not so much: our M1 MacBook Pro’s single fan is identical to the fan in the two-port Intel MacBook Pro 2020 we picked up earlier this year. Not similar—identical.

In other words, what you’re not hearing there is the sound of an aggressive fan curve. This thing likely never spins at more than a fraction of its upper limit. Remember, this same M1 chip performs well in the fanless MacBook Air, so this fan likely doesn’t have all that much to do even under extended load. The M1 is, apparently, just that good.

Hello, World—Meet the M1

Speaking of which, here’s the thing you came here to see: the brand-new M1 package at the heart of both these notebooks.

Apple gave its M1 SoC a very thorough introduction during their keynote on the 10th. Here’s the short version: The M1 is built on a cutting-edge 5-nanometer process (5 nm = smaller transistors for more performance with less energy), like the A14 Bionic in the new iPhones. It packs eight CPU cores (four optimized for performance, and four more for efficiency), and an integrated GPU with either 7 cores or 8, depending on which config you order. (Both use the same M1 chip off the exact same production line, but Apple sorts them in a process known as “binning” where slightly lower-quality silicon results in one GPU core being disabled.)

Next to the shiny silver M1 chip on each board you’ll notice two small black rectangles. Those are the new “integrated” memory chips: 8 GB (2x 4 GB) of SK hynix LPDDR4X memory. Apple calls this UMA, or Unified Memory Architecture. If it looks familiar, it might be because you’ve seen one of our recent iPad teardowns. It’s no surprise that Apple copied some of its own homework here. By baking RAM into the M1 package, each part of M1 (CPU, GPU, Neural Engine, etc) can access the same memory pool without having to copy or cache the data in more than one place. 

This design increases speed and efficiency, but we must admit it is slightly devastating for us, the people who watch Apple’s keynotes crossing our fingers and squinting for a glimpse of user-accessible memory or storage inside their newest devices. User-upgradable parts can significantly prolong the lifespan of any computer (especially entry-level models like the ones we have here). Applications and media files continue to balloon in size, operating systems gain more features, and restricting any computer to a permanently fixed amount of storage or memory is to sentence it to an inevitable early death. We have no doubt Apple could engineer this memory technology to be user-upgradeable (or even just user expandable, maybe?) but we’re not optimistic that it’s top of their priority list. Regardless, we’ll keep hoping ’til next year. Apple says this silicon transition will take two years, and there are no doubt even more performant chips on the way, aimed at professionals with even more demanding needs.

Here’s the complete roster of chips we found in both these machines:

• Apple M1 SoC (Main die + 2x Hynix 4GB LPDDR4X 4266 MHz ICs)
• Intel JHL8040R Thunderbolt 4 Retimer (x2) (basically a Thunderbolt 4 extender/repeater)
• (Western Digital/SanDisk?) SDRGJHI4 – 128GB Flash storage (x2)
• Apple 1096 & 1097 – Likely PMICs
• Texas Instruments CD3217B12 – USB and power delivery IC
• Apple USI 339S00758 – Wi-Fi 6/Bluetooth 5.0 module
• Winbond Q64JWUU10 – 64 Mb serial flash memory
• Renesas 501CR0B
• Intersil 9240H1 (also seen in 2019 MBP 13”)
• National Semiconductor 4881A07
• Siliconix 7655 – 40A battery MOSFET

In terms of differences between the two boards, we noted the Pro comes with a beefier power phase design and a couple extra I/O expander chips, as well as storage chips from Kioxia (formerly Toshiba):

• NXP PCAL6416AHF (marked L16A) – I2C/SMB I/O expander (x2)
• Kioxia KICM232 VD6303 CHNA1 2029 flash storage

Notably absent in this sea of silicon is the infamous T2 chip. For years building up to this 2020 M1 release, Apple has been offloading numerous tasks (especially security/encryption related things) from Intel’s processors to their own custom T2 chip.

Those functions have come home inside the M1, which has a Secure Enclave and a host of built-in security features, just like recent A-series chips. Now that Apple handles so much of the Mac’s silicon in-house, we should probably expect this kind of consolidation to continue. 

Final Thoughts

What to make of our first peek at the future of the Mac? What may seem like superficial changes are really the expression of years of intense work, with hints of a lot more to come. These are the MacBooks Apple has wanted to ship for years, made on its own terms. They’re quiet, fast, and interesting. They’re also less accessible for upgrades and repairs, and are going to be difficult to repair outside Apple’s network for the foreseeable future. There should be a word for proud and disappointed—disaprouded?

Did we miss anything? Got any hot tips for us? Let us know in the social sphere, or in the comments below!